Nitrofurantoin, oral capsule

Highlights for nitrofurantoin

1. Nitrofurantoin oral capsule is offered in both generic and brand-name versions. Brand names: Macrobid and Macrodantin.
2. Nitrofurantoin is also supplied as an oral suspension.
3. Nitrofurantoin oral capsule is prescribed to prevent and treat urinary tract infections caused by specific bacteria.

Important warnings

• Lung inflammation warning: This medication may lead to lung inflammation. Although uncommon, the risk increases if you use the drug for longer than 6 months. Symptoms may include fatigue, fever, chills, cough, chest discomfort, and shortness of breath. Contact your doctor immediately if you notice any of these signs.
• Liver problems warning: This drug can cause liver inflammation or liver injury. If you’re using nitrofurantoin for extended therapy, your doctor will likely monitor your liver function through blood tests. Inform your doctor right away if you develop itching, yellowing of your skin or the whites of your eyes, nausea, vomiting, dark urine, or decreased appetite.
• Nerve damage warning: Nitrofurantoin may result in nerve damage. Symptoms can include numbness, tingling, or pain, especially in your hands and feet.
• Red blood cell damage warning: This medication can cause hemolysis (a form of red blood cell damage). Signs of hemolysis include tiredness, weakness, and pale skin. The condition typically resolves after stopping the drug.
• Diarrhea warning: This medication may trigger mild or severe diarrhea. Notify your doctor promptly if diarrhea occurs while taking this drug. Mild cases may improve after discontinuation. Severe diarrhea may persist and increase your risk of dehydration. In serious cases, your doctor may provide fluids and treat the underlying bacteria with antibiotics. Always consult your doctor before attempting to treat diarrhea on your own.

What is nitrofurantoin?

Nitrofurantoin is a prescription medication available as an oral capsule and an oral suspension. Many patients who wonder, Is Macrobid a strong antibiotic, are actually asking about the effectiveness of nitrofurantoin for urinary tract infections (UTIs).

Nitrofurantoin oral capsule is marketed under the brand names Macrobid and Macrodantin. A generic version is also available and is generally more affordable. However, certain strengths or formulations may differ from the brand-name products.

Why it’s used

Nitrofurantoin oral capsule is used to treat and prevent urinary tract infections caused by susceptible bacteria. It is commonly prescribed for uncomplicated UTIs and plays a targeted role in urinary health.

How it works

Nitrofurantoin belongs to a class of medications known as antimicrobials or antibiotics. A drug class consists of medications that function in similar ways and are often used to manage comparable conditions.

This drug works by killing bacteria responsible for urinary tract infections. It is effective only against certain bacterial strains, which is why proper diagnosis is essential. If you’re comparing options or asking Is Macrobid a penicillin drug, it’s important to know that nitrofurantoin is not a penicillin; it is a distinct type of antibiotic specifically concentrated in the urine to combat UTI-causing bacteria.

Because of its focused activity in the urinary tract, some people ask, “Is Macrobid a strong antibiotic?” Rather than being classified by strength alone, nitrofurantoin is considered highly effective for lower urinary tract infections when the bacteria are susceptible.

Nitrofurantoin side effects

Nitrofurantoin oral capsule can cause drowsiness and may also lead to other side effects.

More common side effects

Common side effects of nitrofurantoin include:

• nausea
• vomiting
• loss of appetite
• stomach pain
• diarrhea
• numbness in your hands and feet
• pain in your hands and feet
• weakness
• dizziness
• headache
• drowsiness

If these symptoms are mild, they may resolve within a few days or weeks. If they persist or become more severe, consult your doctor or pharmacist.

Serious side effects

Contact your doctor immediately if you experience serious side effects. Call 911 if your symptoms feel life threatening or if you believe you are having a medical emergency. Serious side effects and their symptoms may include:

• Lung inflammation. Symptoms can include: tiredness shortness of breath fever chills cough chest pain
• Liver problems. Symptoms can include: itching yellowing of your skin or the whites of your eyes nausea or vomiting dark urine loss of appetite
• Nerve damage. Symptoms can include: numbness or tingling in your hands and feet muscle weakness
• Hemolysis (red blood cell damage). Symptoms can include: tiredness weakness pale skin
• Diarrhea. Symptoms can include: very loose or watery stools bloody stools stomach pain

Disclaimer: Our goal is to provide the most accurate and up-to-date information available. However, since medications affect each individual differently, we cannot guarantee that this list covers all possible side effects. This content is not a substitute for professional medical advice. Always discuss potential side effects with a healthcare provider familiar with your medical history.

Nitrofurantoin may interact with other medications

Nitrofurantoin oral capsule may interact with other medications, vitamins, or herbal supplements you are taking. An interaction occurs when a substance alters how a drug works, which may reduce its effectiveness or increase side effects.

To minimize the risk of interactions, your doctor should carefully review all medications you use. Be sure to disclose all prescription drugs, over-the-counter products, vitamins, and herbs. Speak with your doctor or pharmacist to understand how nitrofurantoin may interact with your current regimen.

Examples of medications that may interact with nitrofurantoin are listed below.

Drugs you should not use with nitrofurantoin

Do not take these drugs with nitrofurantoin. Examples include:

• Antacids such as Gaviscon that contain magnesium trisilicate: These can reduce the effectiveness of nitrofurantoin.
• Probenecid and sulfinpyrazone: Using these medications with nitrofurantoin may cause harmful levels of nitrofurantoin to accumulate in your bloodstream, increasing side effects while decreasing the amount in your urine, making it less effective.

Disclaimer: We strive to present the most relevant and current information. However, because drug interactions vary among individuals, we cannot guarantee that all potential interactions are included. This information does not replace professional medical advice. Always consult your healthcare provider regarding possible interactions.

Nitrofurantoin warnings

Nitrofurantoin oral capsule carries several important warnings.

Allergy warning

Nitrofurantoin may cause a severe allergic reaction. Symptoms can include:

• trouble breathing
• swelling of your throat or tongue

If you experience an allergic reaction, contact your doctor or local poison control center immediately. For severe symptoms, call 911 or go to the nearest emergency room.

Do not take this medication again if you have ever had an allergic reaction to it. Re-exposure could be fatal (cause death).

Warnings for people with certain health conditions

For people with kidney disease: If you have kidney disease, your body may not eliminate nitrofurantoin efficiently. This can result in drug buildup and a higher risk of side effects.

For people with liver disease: You should avoid using nitrofurantoin, as it may worsen liver damage.

Warnings for other groups

For pregnant women: During weeks 0–37 of pregnancy, nitrofurantoin is a category B pregnancy drug. This means:

1. Animal studies have not demonstrated a risk to the fetus when the mother takes the drug.
2. There are not enough human studies to determine whether the drug poses a risk to the fetus.

Consult your doctor if you are pregnant or planning pregnancy. Animal research does not always predict human response.

Nitrofurantoin may cause red blood cell problems in newborns. Therefore, pregnant women should not take this medication:

• at term (38–42 weeks of pregnancy),
• during labor and delivery
• if they believe they are in labor

Contact your doctor if you become pregnant while using this medication.

For women who are breastfeeding: Nitrofurantoin can pass into breast milk and may cause side effects in a nursing infant. Speak with your doctor about whether to continue breastfeeding or discontinue the medication.

For seniors: Kidney function may decline with age, causing drugs to remain in the body longer. This increases the likelihood of side effects. If you are older than 65 years, nitrofurantoin may not be the most suitable option.

For children: Do not use any form of nitrofurantoin in infants younger than 1 month. Macrodantin and its generic form are approved for children older than 1 month. Macrobid and its generic form have not been studied in children under 12 years of age and should not be used in this group.

How to take nitrofurantoin

This dosage guide applies to nitrofurantoin oral capsule. Not all possible dosages and formulations are included. Your prescribed dosage, drug form, and frequency will depend on:

• your age
• the condition being treated
• the severity of your condition
• other medical conditions you have
• your response to the initial dose

Forms and strengths

Generic: Nitrofurantoin

• Form: oral capsule (generic for Macrobid)
• Strength: 100 mg (75 mg nitrofurantoin monohydrate and 25 mg nitrofurantoin macrocrystals)
• Form: oral capsule (generic for Macrodantin)
• Strengths: 25 mg, 50 mg, 100 mg

Brand: Macrobid

• Form: oral capsule
• Strength: 100 mg (75 mg nitrofurantoin monohydrate and 25 mg nitrofurantoin macrocrystals)

Brand: Macrodantin

• Form: oral capsule
• Strengths: 25 mg, 50 mg, 100 mg

Dosage for treatment of urinary tract infections

Adult dosage (ages 18–64 years)

• Macrodantin and its generic form: 50–100 mg four times daily. Duration of therapy varies.
• Macrobid and its generic forms: 100 mg every 12 hours for 7 days.

Child dosage (ages 12–17 years)

• Macrodantin and its generic form: 5–7 mg/kg of body weight per day in four divided doses. Length of treatment may vary.
• Macrobid and its generic form: 100 mg every 12 hours for 7 days.

Child dosage (ages 1 month–11 years)

• Macrodantin and its generic form: 5–7 mg/kg of body weight per day in four divided doses. Treatment duration varies.
• Macrobid and its generic form: Not studied in children younger than 12 years and should not be used in this age group.

Child dosage (ages 0–1 month)

• Macrodantin and its generic form: Should not be used in infants younger than 1 month.
• Macrobid and its generic form: Not studied in children under 12 years and should not be used.

Senior dosage (ages 65 years and older)

Older adults may have reduced kidney function, slowing drug clearance and increasing side effect risk. Your doctor may prescribe a lower dose or adjust your treatment schedule to prevent excessive drug accumulation.

Dosage for prevention of urinary tract infections

Adult dosage (ages 18–64 years)

• Macrodantin and its generic form: 50–100 mg at bedtime.
• Macrobid and its generic form: Not used for prevention of urinary tract infections.

Child dosage (ages 1 month–17 years)

• Macrodantin and its generic form: 1 mg/kg of body weight once daily or divided into two doses.
• Macrobid and its generic form: Not used for prevention of urinary tract infection.

Child dosage (ages 0–1 month)

• Macrodantin and its generic form: Should not be used in infants younger than 1 month.
• Macrobid and its generic form: Not used for prevention of urinary tract infections.

Senior dosage (ages 65 years and older)

Because kidney function may decline with age, your doctor may recommend a reduced dose or modified schedule to lower the risk of adverse effects.

Disclaimer: We aim to provide accurate and current dosage information. However, this may not include every possible dosage. Always follow your doctor’s instructions and consult them regarding the appropriate dosage for you.

Take as directed

Nitrofurantoin oral capsule is typically prescribed for short-term treatment of urinary tract infections. Macrodantin and its generic version may also be used for long-term prevention.

This medication carries serious risks if not taken as directed.

If you stop taking the drug suddenly or don’t take it at all: Your urinary tract infection may persist or worsen. Stopping abruptly may allow bacteria to become resistant, making the drug ineffective in the future.

If you miss doses or don’t take the drug on schedule: The medication may not work properly. Inconsistent dosing can promote bacterial resistance. Maintaining steady levels in your body is essential for effectiveness.

If you take too much: You may develop dangerously high levels of the drug. Overdose symptoms can include:

• nausea
• vomiting

If you suspect an overdose, contact your doctor or the American Association of Poison Control Centers at 800-222-1222 or use their online tool. If symptoms are severe, call 911 or go to the nearest emergency room immediately.

What to do if you miss a dose: Take it as soon as you remember. If it’s close to your next scheduled dose, take only one dose. Never double up to make up for a missed dose.

How to tell if the drug is working: Your urinary tract infection symptoms should improve, including reduced burning, urgency, or frequency.

If you stop taking the drug suddenly or don’t take it at all: Your urinary tract infection may persist or worsen. Stopping abruptly may allow bacteria to become resistant, making the drug ineffective in the future.

Important considerations for taking this drug

Keep these points in mind if your doctor prescribes nitrofurantoin oral capsule.

General

Take nitrofurantoin with food to reduce stomach upset and enhance absorption.

Storage

• Store nitrofurantoin at 68°F to 77°F (20°C to 25°C). Macrobid and generic Macrobid may be stored between 59°F and 86°F (15°C and 30°C).
• Protect the medication from light.
• Avoid storing in damp places such as bathrooms.

Refills

This prescription may be refillable. You should not need a new prescription for each refill if authorized by your doctor.

Travel

When traveling:

• Keep your medication with you at all times. Do not place it in checked luggage.
• Airport X-ray machines will not damage your medication.
• You may need to present the pharmacy label. Carry the original labeled container.
• Avoid leaving the medication in your car, especially in extreme heat or cold.

Clinical monitoring

Your doctor may monitor your health during treatment. If you use nitrofurantoin for long-term prevention of urinary tract infections, periodic blood tests may be performed to assess liver and kidney function.

Are there any alternatives?

Other medications are available to treat urinary tract infections. Depending on your medical history and bacterial susceptibility, some options may be more appropriate. Discuss alternative antibiotics or treatment strategies with your doctor to determine what’s best for you.

Disclaimer: HealthEH strives to ensure that all information provided is accurate, complete, and current. However, this content should not replace the advice of a licensed healthcare professional. Always consult your doctor or another qualified provider before starting any medication. Drug information may change and is not intended to cover all possible uses, directions, precautions, warnings, interactions, allergic reactions, or adverse effects. The absence of specific warnings does not mean a drug or drug combination is safe or appropriate for every patient or condition.